android 实现QQ好友列表（扩展listview:ExpandableListView）

在某些android开发群里，看到有些新手问怎么实现QQ好友列表，其实网上一搜挺多的。接触Android，也才一年的时间，大部分时间花在工作上（解bug。。。），界面上开发很少参与。自己维护的系统应用里，有个ExpandableListView的界面（其实android例子APIDemo也有类似的例子）就在这里写个Demo供新手参考。

ExpandableListView的用法：难点就是重写BaseExpandableListAdapter及提供的数据源。

下面看看继承BaseExpandableListAdapter的适配器：

[java]
<span xmlns="http://www.w3.org/1999/xhtml" style="">package com.xyz.expande;

import java.util.List;

import android.app.AlertDialog;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseExpandableListAdapter;
import android.widget.ImageView;
import android.widget.TextView;

public class ExpandAdapter extends BaseExpandableListAdapter {

    private Context mContext;
    private LayoutInflater mInflater = null;
    private String[]   mGroupStrings = null;
    private List<List<Item>>   mData = null;

    public ExpandAdapter(Context ctx, List<List<Item>> list) {
        mContext = ctx;
        mInflater = (LayoutInflater) mContext
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        mGroupStrings = mContext.getResources().getStringArray(R.array.groups);
        mData = list;
    }

    public void setData(List<List<Item>> list) {
        mData = list;
    }

    @Override
    public int getGroupCount() {
        // TODO Auto-generated method stub
        return mData.size();
    }

    @Override
    public int getChildrenCount(int groupPosition) {
        // TODO Auto-generated method stub
        return mData.get(groupPosition).size();
    }

    @Override
    public List<Item> getGroup(int groupPosition) {
        // TODO Auto-generated method stub
        return mData.get(groupPosition);
    }

    @Override
    public Item getChild(int groupPosition, int childPosition) {
        // TODO Auto-generated method stub
        return mData.get(groupPosition).get(childPosition);
    }

    @Override
    public long getGroupId(int groupPosition) {
        // TODO Auto-generated method stub
        return groupPosition;
    }

    @Override
    public long getChildId(int groupPosition, int childPosition) {
        // TODO Auto-generated method stub
        return childPosition;
    }

    @Override
    public boolean hasStableIds() {
        // TODO Auto-generated method stub
        return false;
    }

    @Override
    public View getGroupView(int groupPosition, boolean isExpanded,
            View convertView, ViewGroup parent) {
        // TODO Auto-generated method stub
        if (convertView == null) {
            convertView = mInflater.inflate(R.layout.group_item_layout, null);
        }
        GroupViewHolder holder = new GroupViewHolder();
        holder.mGroupName = (TextView) convertView
                .findViewById(R.id.group_name);
        holder.mGroupName.setText(mGroupStrings[groupPosition]);
        holder.mGroupCount = (TextView) convertView
                .findViewById(R.id.group_count);
        holder.mGroupCount.setText("[" + mData.get(groupPosition).size() + "]");
        return convertView;
    }

    @Override
    public View getChildView(int groupPosition, int childPosition,
            boolean isLastChild, View convertView, ViewGroup parent) {
        // TODO Auto-generated method stub
        if (convertView == null) {
            convertView = mInflater.inflate(R.layout.child_item_layout, null);
        }
        ChildViewHolder holder = new ChildViewHolder();
        holder.mIcon = (ImageView) convertView.findViewById(R.id.img);
        holder.mIcon.setBackgroundResource(getChild(groupPosition,
                childPosition).getImageId());
        holder.mChildName = (TextView) convertView.findViewById(R.id.item_name);
        holder.mChildName.setText(getChild(groupPosition, childPosition)
                .getName());
        holder.mDetail = (TextView) convertView.findViewById(R.id.item_detail);
  &nb

补充：移动开发 , Android ,